Process for catalytic isomerization of compounds of unconjugated polyethenoid acids



tion is named isomerisation.

cept for wood oils such'as tung oil.

United States Patent Ofifice 3,162,658 Patented Dec. 22, 1964 3,162,658 PRGCESS FOR CATALYTIC ISOMERIZATION OF I CGMPOUNDS F UNCONJUGATED POLY- ETHENOID ACIDS Josef Baltes, Hamburg, and Otto Wechmann and Friedrich Weghorst, Hamburg-Harburg, Germany, assignors to Harburgcr Fettchemie Brinckman & Mergell G.m.b.H., Hamburg-Harhurg, Germany No Drawing. Filed Nov. 21, 1960, Ser. No. 70,412 Claims priority, application Germany, Dec. 2, 1950, H 38,039; Apr. 16, 1960, H 39,186 14 Claims. (Cl. 260--405.6)

The invention relates to a process for a substantially complete catalytic conversion of compounds of unconjuga'ted polyethenoid acids into compounds of conjugated ethenoid acids.

It is known that certain properties of unsaturated fatty acids and their derivatives can be altered by rearrangement of the structure of the double bond, either with respect to their steric position or their position in the carbon chain of the molecule of the fatty acid. This reac- Unsaturated fatty acids having more than one CH=CH group in the chain are also known as polyethenoid acids; molecules with such contiguous groups having double bond between two carbon atoms such as CH=CH-CH=CH- are known as conjugated ethenoid acids, while non-contiguous groups of this configuration will be considered as unconjugated ethenoid acids. The latter ones, namely the unconjugated polyethenoid acids occur in nature in large quantities, while conjugated polyethenoid acids are relatively seldom found in fats or oils of natural origin ex- The latter compound and also its derivatives are of great technical interest and, therefore, many attempts were made to isomerise unconjugated polyethenoid acids to conjugated ones. Theoretically, such a shifting of the double bond is possible because the conjugated form has a lower state of energy than the unconjugated form.

Because of the fact that conjugated unsaturated compounds are obtained by hydrogenation of fats, catalysts,

similar to those used for hydrogenation, have been used for isomerisation, especially nickel catalysts. However,

when using such catalysts, an incomplete isomerisation is achieved, and also unwanted side reactions occur; these side reactions, especially polymerisation and intramolecular cyclisation take place to a more or less large extent.

The known isomerisation with anexcess of alkali metal hydroxide in an aqueous or alcoholic medium leads to a quantitative isomerisation. This reaction is also used for a quantitative determination of unconjugated polyethenoid acids, because the conjugated polyethenoid acids formed by the isomerisation of the unconjugated acids may be determined and measured by spectrophotometric isomerisation at first react, under conditions applied so far, in stoichiometrical amounts or proportions with the functional groups of the fatty acids or their compounds such as carboxyl groups, ester groups, amide groups, and similar groups before an isomerisation can be obtained. Thereby, a corresponding amount. of the catalyst is inactivated and the isomerisation can be achieved only by addition of an excessive amount of catalyst.

The conditions of reaction in the analytical method involve several disadvantages, and in consequence potassium tertiary-butylate in tertiary-butanol is sometimes used as isomerisation agent. In that case the isomerisation can be carried out at a temperature of about C. within a period of about 4 hours, although higher temperatures up to 140 C. are possible, a larger amount than the stoichiometric amount of potassium tertiary butylate always being used.

Surprisingly it has now been found that the quantitative alkali isomerisation of compounds of unconjugated polyethenoid acids, for example, esters of monohydric alcohols, amides and polyamides, and their mixtures can be achieved, if the compounds of unconjugated polyethenoid acids are treated with catalytic amounts of 0.05 to 5% by weight, preferably with 0.3 to 2% of alkali metal alcoholates, especially from monohydric alcohols, at a temperature between 60 and 180 C. preferably between and C. under conditions which avoid inactivation of the catalyst. The method may also be carried out in presence of monohydric alcohols or other polar or nonpolar solvents which are inert with respect to the catalyst. Dimethyl formamide "and dimethyl sulphoxide are especially suitable.

The method according to the invention has the main advantage that isomerisation is possiblewithout using more than stoichionfetrical amounts of alkali metal alcoholates avoiding thereby the serious disadvantages connected therewith.

The catalysts used in connection herewith belong to the group of interesterification or ester interchange catalysts, i.e. catalysts which can accelerate both the interesterification and isomerisation reactions. Their effectiveness decreases according to the following order: cesium, rubidium, potassium, sodium, lithium, magnesium, zinc. Potassium alcoholates are especially useful as isomerisation catalysts for technical purposes not only because of their adequate catalytic activity but also for their partially associated solubility.

Alkali metal compounds of any monohydric alcohol can be'used as catalyst, for example, alkali metalcompounds of methyl alcohol, ethyl alcohol, propyl alcohol, or butyl alcohol and also alkali metal amides. Potassium methylate is preferred. Alkali metals, alkali metal hydrides, organic alkali metal compounds, may be used so long as they react in the reaction mixture to form active catalysts such as alkali metal alcoholates or alkali metal amides. According to the invention the catalyst may be used in the amount of ODS-5% by weight and preferably polyethenoid acid '3 currence of undesired side reactions. A sufficient rate of isomerisation for practical purposes is only observed at temperatures above 60 C. while above a temperature of 140 C. side reactions will be observed to a noticeable extent. The best range of temperature is between 100 and 140 C.

To obtain the maximum activity of the mentioned catalysts certain conditions of reaction have to be fulfilled and maintained. The compoundsof the polyethenoid acids to be isomeris'ed have to be completely free from all compounds which will react with alcoholates', for example, water, free fatty acids, or hydroperoxides. If such compoundsare present the catalyst will be partly or completely inactivated, so that the desired reactions occur only partly or do not take place. Therefore, such compounds should be removed or converted into inert compounds by conventional steps prior to isomeri'zation.

For this isomerization reaction all esters of unconjugated pol ethenoid acids with monohydric alcohols, especially those of the natur'allyoccurring linoleic acid, linolenic acid and arachidonic acid and also of the higher polyethenoid 'acids of marine origin namely tri-, tetra-, pentaand hexethenoid acids may be used, furthermore any amides of the above mentioned fatty acids and all comp'oiinds andde'rivativ'e's of these fatty acids, the functional groups of which are incapable of an inactivating reaction with the catalyst. According to the invention the isomerization reaction can be controlled in such a way that a partial conjugation of them acids and more highly unsaturated fatty acids is favored. I The is'ome'rization of the fatty acid esters and amides can be carried out so that intere'sferification or aminolysis takes place at the same time.

To control the progress of isomerization, a test is used as described by B. Sre'enivasan and J. B. Brown in Journal of the American Oil Chemists Society, volume 33, page 521 (1956), and volume 35, page 89 (1958). According to this method the original substrate, the final product and also samples of the reaction mixtiire withdrawn at certain time intervals are analysed. The extent of the isomerization is given by the measured ris.

values in relation to the determined by the above method. The extent of isomerization of diethenoid acids is given by El? 234 m determined- (Ell 268 m determined Ea, 234 ms analyticaldetermined E} 268 ma 1 analytical E1 2 268 m In this it is assumed that the method of Sreenivasan and Brown results in complete isomerization.

In the examples the percentage isomerization is calculated on the basis offatty acids, I 7

The invention is illustrated by, but is not intended to be limited to, the following detailed examples showing various embodiments of the invention.

Example 1 5000 g'. of the distilled methyl ester of soya bean fatty acids containing 6.3% linolenic acid and 46.0% linoleic acid, combined as esters, were heated to a temperature of 120 C. and mixed with 50 g. of dried potassium methylate. The mixturesoon turned into a brownish color and was allowed to stand for a period of hours being agitated from time to time. At certain time intervals several samples were taken and, after the catalyst had been removed by washing, they were used for spectrophotometrical determination of conjugated polyethenoid acids. The results are shown in the following table:

Percent isom- Percent isom- Reaction time in minutes erization of erization of triethenoid diethenoid esters esters The results show that about 97% of thetotal ester of unconjugated polyethenoid acids is converted into the ester of the conjugated polyethenoid acids. Allowing for the margin of error of spectrophotometrical methods the isomerization may be considered as practically complete.

Within a range of temperature between 100 and C. parallel experiments Withthe same material and the same catalyst gave corresponding results. At a temperature of 80 C. the reaction is considerably slower, and at a temperature of 60 C. only a very slow reaction rate was observed. The isomeriia'tion is also slowed down if the amount of catalyst decreases, and is hardly notice; able with an amount of 0.1% potassium methylate. An increase of the amount of the catalyst above 1% doe not accelerate the reaction noticeably, I

Analogous results were also obtained with ethyl, propyl and butyl esters of soyabean acids; in addition, potassium ethyla'te, propylate and butylate instead of potassium niethylate "gave the same results.

Example 2 A distilled methyl ester of soya bean oil acids having the same composition as d escribed in Example 1 was used assubstrate. v The catalyst was prepared by grinding potassium methylate with difierent alcohols in a molar ratio of 1 mol of potassium methylate to 0.5 2 mols of methyl alcohol, ethyl alcohol, normal or isopropyl alcohol or normal or secondary butyl alcohol or lauryl alcohol or benzyl alcohol respectively. In this way solid or semi-solid compositions were formed which were added to the mixture heated up to the necessary reaction temperature and the catalyst was quickly and uniformly distributed by agitation- I,

Thefollowing run may be taken as an example. 5,000 g. of the methyl ester of soya bean fatty acids were reacted at a temperature of 140 C. The catalyst consisted of a mixture of SQ g. of potassium methylate and 53g. of secondary butyl alcohol. The run, was made as described in Example 1, Theprogress of the isomerization is shown by the results of the following table:

- Percentlsom- Percentisom- Reaction time in minutes erization of erization 0t triethenoid dietheuoid esters esters After aperiod of 45 minutes the isomeri'zation of the ester of linolenic acid wasalrc'ady complete, while after a period of 90 minutes the ester of the linoleic acid was completely isomerized. Compared with the run described in Example 1 the reaction time had been decreased 'to less than one-third;

This run also shows that the range of temperature between 100 and 140 C. is most favorable for isomerization. The optimal composition of the catalyst is between a molar ratio of 1 mol of potassium methylate to 1-2 mols of alcohol where ethyl alcohol, propyl alcohol or butyl alcohol is used, while for methyl alcohol the best ratio is 1:1.5-2. Here, the optimum concentration of the catalyst was also 0.5 to 1% of potassium methylate.

Example 3 3,000 g. of distilled propyl ester of cotton seed fatty acids containing 45.5% linoleic acid combined as ester, were heated to a temperature of 140 C. and mixed with a catalyst composition with stirring; the catalyst was obtained from g. potassium methylate and 22 g. of isopropyl alcohol. When the reaction temperature was maintained at such a level with occasional stirring, the isomerization was 85% complete after a period of 15, minutes; after a period of minutes an isomerization of 98% had taken place; after a period of 90 minutes an isomerization of 100% was obtained.

After cooling of the reaction mixture and removal of the catalyst by washing with hot water an extremely light colored product was obtained, as it was in the Examples 1 and 2.

Example 4 With mixtures of esters containing large amounts of linolenic acid and small amounts of linoleic acids a superimposition of isomerization reactions of the esters of linolenic and linoleic acid was observed. The rate of isomerization of the triply unsaturated acid is substantially larger than the corresponding rate of the doubly unsaturated acid. However, during the further reaction the content of the conjugated tri-ethenoid acid is reduced, while the content of conjugated di-ethenoid acid exceeds the value calculated from the content of linoleic acid. The reason for this is, on the one hand, that the isomerization of linolenic acid occurs in two steps whereby a conjugated di-ethenoid acid is formed during the first step, while the 3 conjugated tri-ethenoid acid is formed only during the second step. On the other hand, the ester of the conjugated tri-ethenoid acid undergoes a further change during treatment whereby a cyclic di-ethenoid acid ester is formed. This will be illustrated by the following typical example.

5,000 g. of distilled methyl ester of linseed oil acids containing 43.8% of linolenic acid and 14.3% of linoleic acid, combined as esters were heated to a temperature of 120 C. and mixed with stirring with a catalyst prepared from g. of potassium methylate and 43 g. of isopropyl alcohol. The mixture immediately turned a dark brown color and was maintained at a temperature of 120 C. with occasional stirring. Samples were taken periodically and the content of the several conjugated acids was determined spectrophotometrically. The results are given in the following table.

Percent isom- Percent isom- Reaction time in minutes erization of erization of trietheuoid dicthenoid esters esters minutes and an extremely light colored product was obtained containing 53.0% of conjugated fatty acids, which corresponds to a total isomerization of about 92%.

By changing the temperatures and concentration of the catalyst it is easy to obtain a total isomerization of almost 100%. For this purpose a temperature of 120 C. is best,

and the amount of catalyst may be twice as much as in the run described above. Under these conditions a product was obtained after a period of 1 /2 hours in which the unconjugated poly-ethenoid fatty acids were converted into conjugated acids up to an extent of 98%.

Example 5 3,000 g. of the methyl ester of linseed oil fatty acids were heated in a three necked reaction flask having a capacity of 5,000 ml. and equipped with a stirrer, condenser, thermometer, gas inlet tube and gas outlet tube. The ester was heated up to a temperature of 120 C. under a nitrogen blanket. Whilst continuously stirring and introducing nitrogen at a low rate 200 ml. of a 14% solution of potassium tertiary butylate in tertiary butanol were added within a period of 10 minutes during which tertiary butanol and some methyl alcohol was distilled off. The mixture was maintained under these conditions at a temperature of 120 C. for 3 hours after which the mixture was cooled and washed several times with water and dried under vacuum.

To measure the extent of the isomerization obtained, samples of the material were tested spectrophotometrically before and after isomerization with respect to the content of unconjugated and conjugated fatty acids, giving the following results:

Isomerization After further analytical isomerization Before After Percent linoleic acid Percent linolenic acid Percent total unconjugated polyethenoid acids Percent isomerizcd di-ethenoid acids Percent total isomer 01yethenoid acids Example 6 1,000 g. of the methyl ester of soya bean fatty acids, 350 ml. of n-heptane and 310 ml. of tertiary butyl alcohol were heated to boiling in a glass flask of- 2,000 ml. capacity being equipped with an inserted thermometer a rectification column having 12 theoretical plates and a condenser. Then 50ml. of'a 5% solution of potassium tertiary butylate in tertiary butanol were added and heated under complete reflux conditions for a period of 2 hours. The content of the flask was at a temperature between and C. As soon as the distillate began to separate into two phases the alcoholic phase was continuously removed and the heptane phase was returned to the rectification column. During this treatment several samples of the content of the still were taken at certain time intervals in order to analyse their content of conjugated and unconjugated fatty acids and also the amount of tertiary butyl ester. The time of the treatment and the analytical results are shown in the following table:

While the starting material contained 55.7% of linoleic acid and 8% of linolenic acid, combined as ester, the further analytical isomerization and the corresponding spectrophotometri'cal test of the completely esterified product gave a content of 48.3% of isomerized dieth'enoid fatty acids and 6.8% of isomerized tri-ethenoid fatty acids. Taking into account the difference between the molecular weight of the methyl ester used and the butyl ester obtained, a practically complete isomerization of the 11'nc'onjuga'ted p'olyethenoid acid is obtained. 7 This was achieved after a treatment of about 20 hours, namely before the methyl ester used had been-quantitatively converted into the corresponding tertiary 'butyl ester.

Example 7 By using the apparatus as described in 'Example 5, 2,800 g. of distilled methyl "ester of fish oil fatty acids were heated to a temperature of 140 'C. to which 300 ml. of a hot solution of'caesium tertiary butylate in tertiary butanol were -added. After'having distilled the bulk of the tertiary'but'anol'in'a stream of nitrogen, the mixture'was stirred unde'r'vacuum atthe temperature of 1 40 C. for tWo further hours, so that the complete time of'treatmentwa's two and a half hours.

Samples were taken from'the mixture at intervals of 30 minutes and were measured spectrophotornetrically. The results are shown in the folloWingt-able:

This shows that the amides of unconjugated polyethenoid acids are completely isomerized with small amounts of catalysts within a relatively short time.

Example 9 Example 2 was repeated with 50 g. of sodium amide as catalyst insteadof the 50g. potassium methylate. The obtained degree of isomerisation was the same as in Example 2.

Example 10 Example 2 was repeated with g. potassium metal as catalyst instead of the g. potassium methylate. The obtained degree of isomerisation was the same as in Example 2.

Example 11 Further After 30 After After After120 analytical minutes minutes minutes minutes isomerination E}. g at 375 m 1, 06 1. 14 1. 27 1. 3a 7. 97

(Conjugated hexa ethenoid acid.)

12 at 346 m 5 11 4 e 49 6 1s 37 17 1 mm M (Conjugated penta ethenoid acid.)

Efi at 315 my 34. so 35. 50 39. 5e '35. 98 so. 53

(Conjugated tetra. ethenold acid.)

E% at 268 my 165. 96 166.03 163.89 143. 49 112. 83

(Conjugated triethenoidacid'.)

E} g at 233 m 163. 83 163. 36 165. 49 150.11 113. 0

(Oonjugated diethenoid acid.)

-Itis evident that the isomerization leadsto a substantially complete conversion of the unconjugated polye'tlienoid acids to acids containing-conjugated systems. After 30 minutes the isomeriZation-is practically completed. This exampleshows'furtherniore, that-the isomerization could also be carried out partially, ile. unconjugated polyethenoid acids havin'g'3 or moredouble bonds maybe converted into'the correspondingconjugated 'diethen'oid acids of tri ethe'noid acids.

-Example 8 3600 giofthe methylester-of soya bean fatty acids were heated to'gether with lSO g. of-ethylene diamine to a temperature of 140160 CJfor aperiod of four hours, after which the methyl alcohol liberated was removed under vacuum. -'-The-mixture'-partially converted -into the diamides contained 6.3% linolenic acid and 4 9.4% linoleic acid in the combined form. After heating to a temperature of 120 C. 10g. of potassium methylate were addedwith stirring and the mixture was left at this temperature for one hour. The catalyst was removed by adding 50 g. of fullers'earth followed by filtration. The light colored product thus obtained contained 6.3% isomerized tri-ethenoid acid and 49.1% isomerized di-ethenoid acid, corresponding to a total isomerization of nearly In this run the amount of ethylene diamine used was equivalent to the content of polyethenoid fatty acid.

understood that the process of this invention is broadly applicable to any unconjugated polyethenoid acid compounds and. products containing them. The unconjugated polyethenoid'acid compounds used as starting materials are monohydric alcohol esters, or amides or polyamides of the unconjugated polyethenoid acids which can be used in mixture with each other or with other. materials. As examples of such monohydric alcohol esters, amides and polyamides the following are mentioned: the esters of primary, secondary and tertiary aliphatic alcohols with 1-18 carbon atoms, of primary, secondary and tertiary aromatic alcohols, the amides of ammonia aliphatic and aromatic monoamines and polyamides of aliphatic and aromatic diamines and triamines. It will be observed that the aforementioned alcohols can be called hydrocarbyl alcohols, and the amines can be called hydrocarbyl mono and polyamines. The esters of the aliphatic alcohols disclosed in the examples can also be termed esters of alkanols. In all cases, these starting materials are treated substantially in a manner analogous to that described in the above Examples 1-8.

The catalysts used in carrying out the present invention are alcoholates, especially of monohydric alcohols with 1-18 carbon atoms, of the alkali metals-potassium, sodium, lithium, rubidium, cesium, such as alkali metal alcoholates of methyl, ethyl, propyl, butyl, tertiary butyl, lauryl, stearyl, oleyl, benzyl alcohols, alkali metal amides, and substances, such as alkali metals, alkali metal hydrides, and organic alkali metal compounds, e.g. triphenyl sodium, which form in the reaction mixture the mentioned active isomerisation catalysts. The alkali metal alco holates can be called alkali metal hydrocar'oyl alcoholates. The specific alcoholates set forth in this paragraph except that from benzyl alcohol can be termed alkali metal alkanolates.

The unconjugated polyethenoid acid compounds are treated with the catalysts of the invention in amounts of 0135- 13%, preferably with 03-22% based on the weight of said compounds, at a temperature between 60 and 180 1, and preferably between 190 and 140 C. under conditions which do not cause inactivation of the catalyst. The alkali metal alcoholates described above can be used as catalyst in mixture with a monohydric aliphatic or aromatic alcohol, e.g. methyl, ethyl, nor isopropyl, nor secondary butyl alcohol, or lauryl, palmityl, oleyl alcohols, benzyl alcohol, in a proportion of one mol of alkali metal alcoholate per 0.1-5.0 mols and preferably per 0.54.0 mols of said monohydric alcohols. Furthermore, said alkali metal alcoholate catalysts can be also added to the starting materials to be isomerized in the form of solutions of the alkali metal alcoholates in said monohydric alcohols.

As already mentioned above, the process of the invention can be carried out in the presence in the reaction mixture of solvents which do not interfere with the activity of the catalyst employed. As further examples of such solvents-which are used preferably in an amount of to 50%, based on the weight of the starting material to be treated-the following are mentioned: methyl, ethyl, isopropyl, butyl, amyl alcohol, pentane, hexane, heptane, heptylene-(l), ctylene-I, benzene, toluene.

As likewise already mentioned above, according to a modification of the invention alkali metals or alkali metal compounds which reacts in the reaction mixture with components thereof with the formation of active isomerization catalysts, can be added to the starting material to be isomerized in carrying out the process of the invention.

The term inert solvent is used herein to denote volatile solvents which do not interfere with the activity of the catalyst employed, such as aliphatic or aromatic hydrocarbons e.g. dimethyl formaniide or dimethyl sulfoxide.

The percent and par-ts mentioned herein are by weight if not otherwise stated.

The compounds of conjugated fatty acids obtained by the method of this invention, or mixtures containing these compounds, are valuable industrial products which can be used in many ways. For instance their polymerisation by heating takes place at a very fast rate and, therefore, the products can be converted into light colored polymer compounds by moderate heating, eg at 260280 C. The polymers thus formed can be used as ingredients of lacquers or coating compositions in conventional manner. Furthermore the conjugated fatty acid compounds of this invention can be used as ingredients of plasticizers for organic plastic materials, and as reaction components in the preparation of resins, such as alkyd resins or maleinate resins, in conventional manner.

What is claimed is:

1. A process for the catalytic isomerization of unconjugated polyethenoid fatty acid compounds to conjugated isomers thereof, by treatment of the starting material selected from the group consisting of unconjugated polyethenoid fatty acid esters of monohydric alcohols, said alcohols being hydrccarbyl alcohols having 1 to 18 carbon atoms; and unconjugated polyethenoid fatty acid amides from hydrocarbyl mono and polyamines, consisting essentially of treatment of the starting material consisting essentially of one of these compounds with 0.85- 5.6% by weight of a catalyst selected from the group consisting of alkali metal hydrocarbyl alcoholates and alkali metal amides at a temperature between 60 C. and 186 C.

2. A process according to claim 1 in which said compound is an ester of a hydrocarbyl alcohol which is an alkanol.

3. A process according to claim 2 in which said catalyst is an alkali metal alkanolate.

4. A process according to claim 1 wherein said compound is a methyl ester of an unconjugated polyethenoid fatty acid.

5. A process according to claim 4 wherein said alkanolate is a methylate.

6. A process according to claim 2 wherein said catalyst is formed in situ from an alkali metal and an alkanol.

7. A process according to claim 1 in which the catalyst is used in an amount of 0.3 to 2% by weight of the polyethenoid fatty acid compound.

8. A process according to claim 1 carried out at a tem perature between C. and C.

9. A process according to claim 1 in which the catalyst is a mixture of 1 mole of the alkali metal alcoholate with 0.5 to 2.0 moles of a monohydric hydrocarbyl alcohol containing 118 carbon atoms.

10. A process according to claim 9 in which the alcoholate is an alkanolate and the alcohol is an alkanol.

11. A process according to claim 1 in which the catalyst is a potassium alkanolate.

12. A process according to claim 1 in which the isomerization is carried out in an inert solvent.

13. A process according to claim 12 in which the solvent is dimethyl formamide.

14. A process according to claim 12 in which the solvent is dimethyl sulfoxide.

References (Cited by the Examiner UNlTED STATES PATENTS 2,242,230 5/4l Burr 260405.6 2,418,454 4/47 Auer 260-405.6 2,614,937 10/52 Baur et al. 260-4056 2,688,626 9/54 Miller 260405.6

OTHER REFERENCES Turk et al.: Paint, Oil and Chemical Review, 10-11 (December 1943).

CHARLES B. PARKER, Primary Examiner. ABRAHAM H. WINKELSTEIN, Examiner. 

1. A PROCESS FOR THE CATALYTIC ISOMERIATION OF UNCONJUGATED POLYETHENOID FATTY ACID COMPOUNDS TO CONJUGATED ISOMERS THEREOF, BY TREATMENT OF THE STARTING MATERIAL SELECTED FROM THE GROUP CONSISTING OF UNCONJUGATED POLYETHENOID FATTY ACID ESTERS OF MONOHYDRIC ALCOHOLS, SAID ALCOHOLS BEING HYDROCARBYL ALCOHOLS HAVING 1 TO 18 CARBON ATOMS; AND UNCONJUGATED POLYETHENOID FATTY ACID AMIDES FROM HYDROCARBYL MONO AND POLYAMINES, CONSISTING ESSENTIALLY OF TREATMENT OF THE STARTING MATERIAL CONSISTING ESSENTIALLY OF ONE OF THESE COMPOUNDS WITH 0.055.0% BY WEIGHT OF A CATALYST SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL HYDROCARBYL ALCOHOLATES AND ALKALI METAL AT A TEMPERATURE BETWEEN 60*C. AND 180*C. 